[Qemu-devel] [RFC PATCH 4/4] pci-assign: Add MSI affinity support

[Alex Williamson <alex.williamson@redhat.com>]

Track the last MSIMessage programmed so we can determine when it has
changed and update the routing to the guest.  We track MSI-X for
consistency, but we don't do anything with it here.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/kvm/pci-assign.c |   29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/hw/kvm/pci-assign.c b/hw/kvm/pci-assign.c
index 3e667d1..500c62c 100644
--- a/hw/kvm/pci-assign.c
+++ b/hw/kvm/pci-assign.c
@@ -133,6 +133,7 @@ typedef struct AssignedDevice {
     int msi_nr;
     struct {
         int virq;
+        MSIMessage msg;
     } *msi;
     MSIXTableEntry *msix_table;
     hwaddr msix_table_addr;
@@ -1009,6 +1010,7 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev)
         assigned_dev->msi = g_malloc(sizeof(*assigned_dev->msi));
         assigned_dev->msi_nr = 1;
         assigned_dev->msi[0].virq = virq;
+        assigned_dev->msi[0].msg = msg;
         if (kvm_device_msi_assign(kvm_state, assigned_dev->dev_id, virq) < 0) {
             perror("assigned_dev_update_msi: kvm_device_msi_assign");
         }
@@ -1021,6 +1023,27 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev)
     }
 }
 
+static void assigned_dev_update_msi_msg(PCIDevice *pci_dev)
+{
+    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
+    uint8_t ctrl_byte = pci_get_byte(pci_dev->config + pci_dev->msi_cap +
+                                     PCI_MSI_FLAGS);
+    MSIMessage msg;
+
+    if (assigned_dev->assigned_irq_type != ASSIGNED_IRQ_MSI ||
+        !(ctrl_byte & PCI_MSI_FLAGS_ENABLE)) {
+        return;
+    }
+
+    msg = msi_get_message(pci_dev, 0);
+
+    if (msg.address != assigned_dev->msi[0].msg.address ||
+        msg.data != assigned_dev->msi[0].msg.data) {
+        kvm_irqchip_update_msi_route(kvm_state, assigned_dev->msi[0].virq, msg);
+        assigned_dev->msi[0].msg = msg;
+    }
+}
+
 static bool assigned_dev_msix_masked(MSIXTableEntry *entry)
 {
     return (entry->ctrl & cpu_to_le32(0x1)) != 0;
@@ -1076,6 +1099,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
             return r;
         }
         adev->msi[i].virq = r;
+        adev->msi[i].msg = msg;
 
         DEBUG("MSI-X vector %d, gsi %d, addr %08x_%08x, data %08x\n", i,
               r, entry->addr_hi, entry->addr_lo, entry->data);
@@ -1183,6 +1207,10 @@ static void assigned_dev_pci_write_config(PCIDevice *pci_dev, uint32_t address,
         if (range_covers_byte(address, len,
                               pci_dev->msi_cap + PCI_MSI_FLAGS)) {
             assigned_dev_update_msi(pci_dev);
+        } else if (ranges_overlap(address, len,
+                                  pci_dev->msi_cap + PCI_MSI_ADDRESS_LO,
+                                  10 - PCI_MSI_ADDRESS_LO)) {
+            assigned_dev_update_msi_msg(pci_dev);
         }
     }
     if (assigned_dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX) {
@@ -1561,6 +1589,7 @@ static void assigned_dev_msix_mmio_write(void *opaque, hwaddr addr,
                 msg.address = entry->addr_lo |
                     ((uint64_t)entry->addr_hi << 32);
                 msg.data = entry->data;
+                adev->msi[i].msg = msg;
 
                 ret = kvm_irqchip_update_msi_route(kvm_state,
                                                    adev->msi[i].virq, msg);